Interlocking system for railroads



Jan. 16, 1923.

E. C. LARRY. INTERLOCKING SYSTEM FOR RAILROADS.

I FILED JUNE 4, I920.

3 SHEETSSHEE1 1.

V 1,442,684,. E, C. LARRY. INTERLUCKING SYSTEM FOR RAILROADS. FILED JUNE4, 1920 3 SHEETSSHEET 2.

F I GE;

Jan; 16, 1923p E, C LARRY! INTEBLDGKING STEM FOB BA LRQ DS.

FILED JUNE h 1820: HEET5 H 3' Fl a.

Patented Jan. 16, 1923.

ater.

UNETEO STATES PATENT OFHQE.

EDWIN C. LARRY, OF ROCHESTER, NEW YORK, ASISIGNOR TO GENERAL RAILVTAYSIGNAL COMPANY OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

INTERLOCKING SYSTEM FOR RAILROADS.

Application filed June 4, 1920.

To all whom it may concern:

Be it known that I, EDWIN'C. LARRY, citizen of the United States,residing at Rochester, in the county of Monroe and State of New York,have invented certain new and useful Improvements in lnterlockingSystems for Railroads, of which the following is a specification.

This invention relates to interlocking sys tems for railroac s. v

lVhen the switches, signals, and other functions are few in number andcomparatively close together, they may be satisfactorily operatedmechanically, but where there are one or more functions at a distancefrom the tower, it is desirable to operate these by power, and in orderto retain the same kind of interlocking between the levers, it ispreferable to control these power operated functions by a mechanical.lever. The present invention relates more particularly to a constructionand arrangement of parts and circuits suitable for incorporation with amechanical lever so as to permit the safe and reliable operation ofswitches or other functions at a distance from the tower. The inventionfurther contemplates the use of alternating current as the source ofpower for operating these distant functions, and the devices associatedwith the lever, particularly the indication mechanism, are constructedand adapted for use with such alternating current.

Other features and advantages of the invention will appear hereinafter.

In describing the invention in detail reference will be made to theaccompanying drawings in which:

Figure 1 is a general view of a mechanical lever of well knownconstruction, showing the application thereto of an electric lock orindication mechanism embodying the in vention;

Fig. 2 is a longitudinal section through the electric lock;

Fig. 3 is a transverse section through the lock taken on the line 3-3 inFig. 2;

Fig. 4 is afragmentary horizontal section taken substantially on theline 44 in Fig. 2;

Figs. 5, 6 and 7 are detail views showing the position of the partsduring different stages of the operation of the electric lock; and iFig. 8 is a diagrammatic view in the Serial No. 386,464.

nature of a circuit diagram showing the circuit connections of a systemembodying the invention.

Fig. 1 shows one lever of the well known naxby and Farmer interlockingmachine, with the improvement constituting the present invention appliedthereto. The lever L is fastened to a shoe 1 which is mounted on a pin 2supported by the bottom girder 3 of the machine in the usual way. Alatch handle t is pivoted on the lever L and is connected by a rod 5 toa rocker die 6, which is pressed down by a spring 7. The die 6 engageswith shoulders 88 on the fixed quadrant, and the die slides in a curvedslot 9 in the rocker 10 pivotally supported at its middle on a pin 11.The rocker 10 is connected by a link 12 to the locking shaft 13 whichactuates the mechanical interlocking of the machine in the usual way,said interlocking being supported upon the bed 14.

The electric lock or indication mechanism M embodying this invention issupported above the locking bed 14 in a suitable manner, and isconnected by a rod 15, having an adjustable clevis at its lower end, tothe rocker 10. The indication mechanism M prevents movement of the rod15 under certain conditions, and this in turn prevents rocking movementof the rocker 10, with the result that the lever cannot be unlatched, orthe mechanical interlocking released, as the case may be.

A circuit controller for governing the application of current to thedistant switch or other function may be of any suitable construction,and for simplicity a circuit controller of the rotary drum type isillustrated. This circuit controller comprises a drum 16 of insulatingmaterial which is supported in suitable bearings and is provided withcontact strips or segments, as 1718, fastened on its periphery. Contactsprings, as 19-20. are supported and insulated in any suitable manner inposition to cooperate with the strips 17-18 on the drum, therebyestablishing certain circuit connections in the different positions ofthe drum. The drum 16 is arranged to be driven by a crank 21, which isconnected by a link 22 to an adjustable block 23 on the tail-piece 24 ofthe lever. v

Referring to Figs. 2 to 7. the locking mechanism M comprises a suitablebase or framework 13 having two uprights 25-25 supporting a rotarycircuit controller drum 26. This drum 26 has anumber of contact strips27 fastened thereto, and a number of contact fingers or springs 28,supported by a panel 29 of insulating material, cooperate with saidstrips. Also supported by the uprights 25 25 is an indication magnetcomprising two cores 30 having pole pieces 31. On each core 30 is a coil32 which is shorter than said core; and surrounding the cores 30 at theend opposite from the coils 32 are one or more yokes of copper orsimilar electrical conducting material. tlleeves 31 are used to hold theyokes 33 and the coils 32 in place. An angle lever 35 is pivotallymounted on a pin 36 in the upper end of the upright 25,, and the shortend of this angle lever carries an armature 37 disposed opposite thepole pieces 31.

The locking mechanism comprises a sector 38 which is journaled betweentwo standards 39 on a pin 10. This sector 38 is connected to the rod 15which attached to the rocker 10, so that said sector moved back andforth as said rocker is shifted. The sector 38 is also connected by alink d1, having universal connections at its ends, to a crank armconnected to the shaft of the circuit controller drum 26. The upper edgeof the sector 38 is cut away to leave normal and reverse lockingshoulders 42*" and 42-; and pivotally supported on said sector arenormal and reverse latches 13 and 13 which are pressed by springs '14inward against a stop 15 to the position shown in Fig. 2. The outer endsof these latches d3 l-3 are concentric or flush with the outer edge ofthe sector 38; and when these latches are in their innermost positionagainst the stop 15 they lap past the locking shoulders 42 4-2 as shownin Fig. 2. A U-shaped dog 16 is pivotally connected to the long arm ofthe lever 35 and rests upon the upper edge of the sector 38. The sidesof this dog 46 are guided by vertical slots .in the upper ends of thestandards 39. The upper face oi the cross connecting member of said dog16 is beveled in opposite directions as shown in dotted lines in Fig. 2,and these beveled 'taces cooperate with a beveled piece attached to acurved strip 48 fastened to the outer edge of the sector 38, so as toforce the dog downward between the two locking shoulders 4(2 42 Asuitable cover 19 is provided for the locking mechanism.

Fig. 8 shows an electric lock embodying the invention applied to a wellknown type of dynamic indication interlocking system. Some parts of thissystem of interlocking, being well known and also disclosed in otherpatents and applications, have been shown conventionally, and theirconstruction and operation will be only briefly referred to in so far asis necessary to obtain a clear understanding of the present invention.In the diagrammatic illustration oi Fig. 8, SM designates generally acircuit controller and motor of a suitable switch machine, such as isdisclosed for example in the patent to V. K. Howe, 1,288,595, December2st, 1918. IS designates the well known indication selector, and CP across protection relay operable upon alternating current but not directcurrent and adapted to interrupt the supply of current to the switchmachine when crosses or other improper connections exist. The source ofcurrent is illustrated as a transformer T which is supplied with currentfrom a suitable line circuit connected to the generator G. The circuitcontroller C and the electric. lock have been shown in a simplifiedmanner.

Opcratz'0n.-Assume the parts to be in the normal position shown in F 8,and it is desired to move the switch to the reverse position. Theoperator presses the latch 4. and if the mechanical interlocking permitsmovement of the link 10, the die 6 is raised above the locking shoulder8,. so that the lever L may be pulled to its other position. During thismovement of the rocker 10, the sector 38 is moved from the positionshown in Fig. 2, to that shown in Fig. 5 where the dog 16 engages thereverse shoulder 42 The sector 38 can not, therefore, be moved furtherin this counterclockwise direction until the dog 16 is raised, andconsequently, the rocker 10 cannot move and prevents the final unlockingmovement of the shaft 13. lVhen the lever L is moved, the drum 16 of thecircuit controller C is moved from the position shown in F ig. 8 to theposition where the contact strips 17-18 bridge the pairs of contactsprings 1920, thereby establishing the reverse operating circuit, whichmay be traced as follows: commencing at one terminal of the transformerT, wire 50, contact 51 of the cross protection relay GP, wires 52. 53,indication selector magnet 5%, wire contacts 17-19, wire 56, reverseoperating wire R, thence through the contacts and motor of the switchmachine back along the common return connection 100 through the contact57 of the cross protection relay UP and wire 58 back to the transformerT. This circuit supplies current to the switch machine which acts tomove the switch points to the reverse position in the usual way. Whenthe switch machine completes its cycle of operation, the motor (which isespecially constructed so as to generate direct current dynamically)sends indication current out along the wire N, through wire 60, contacts1820, wire 61, contacts 62, 63 and 641 of the indication selector(contact bar 63 havin been shifted by 'energization of mag net 54 wire65, indication magnet 32, wire 66, cross protection relay GP, and wire67 back along common wire 100 to the motor. This indication current,being direct current, attracts armature 37 and raises dog 46. As soon asthe dog 46 is raised clear of the latch 43 this latch is swung by itsspring 44 underneath said dog. (See Fig. 6). The operator now maycomplete the movement of the lever and the rocker 10, the dog at beingnow moved to the position shown in Fig. 7, thereby releasing themechanical interlocking. The operation of moving the function from thereverse position back to the normal position is analogous to thatdescribed, and the circuits involved can be readily traced.

The latches 13 are provided so that the op erator is not compelled tocomplete the operation of the lever just atthe instant the indication isreceived. In other words, the indication current, although it flows onlymomentarily, gives a permanent release. This feature is of importancebecause it does not require the operator to give any attention to thelever while the function is operating and the indication is beingreceived, and also because it obviates the inclination of the op eratorto bind or jam the indication mechanism, as he might otherwise do ifrequired to take advantage of the indication just at the instant it wasreceived.

The indication magnet, while operating freely when supplied with directcurrent, will not act to attract its armature 37 when supplied withalternating current. The copper yoke 33 constitutes, in effect, ashort-circuited turn around each core 30; and when alternating currentflows through the coils 32, the alternating flux induces current in theyoke 83, which in accordance with well known laws, opposes the passageof flux through the cores and the armature 37 In this way, it is assuredthat no false indication will be received on account of alternatingcurrent from the operating source finding a path in some way through theindication magnet.

In the arrangement shown in Fig. 8, the circuit controller governing theoperating and indication circuits, is operated by the tail-piece of thelever. I prefer this arrangement when the lever is used for controllinga switch; but when a signal is governed by the lever, the circuitcontroller drum 26 and associated parts coupled to the sector 38 may beemployed, and the circuit controller C omitted. It will be evident thatthe circuit controller C, being operated by the tailpiece 24 of thelever, may have a much greater range of movement than in the case of thecircuit controllerdrum 26 connected to the sector 38. This limitedmovement makes the use of the latter circuit controller undesirable inthe case of a switch which requires both normal and reverse locking andnormal and reverse indication circuits; whereas in the case of thesignal which requires only reverse locking and a reverse indicationcircuit, the limited movement of the circuit controller drum 26 issufficient.

I desire to have it understood that the construction and arrangement ofparts and circuits illustrated is susceptible of change, and that myinvention is not limited, to the exact construction and arrangementshown.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. An electric lock for mechanical levers comprising a base and twouprights, a circuit controller drum pivotally supported between saiduprights near their upper ends, a sector for operating said drum andhaving a locking shoulder, a lock dog cooperating with said sector, andmeans for actuating said lock dog comprising magnetic cores extendinglengthwise of and below said control drum and supported by saiduprights, an armature connected to said lock dog and disposed oppositeone end of said cores, energizing windings on the other end portion ofsaid cores, and a single conducting yoke on the ends of the coresadjacent the armature, said yoke being spaced from said windings,whereby said armature will be actuated to unlock said sector by directcurrent but not by alternating current supplied to said windings.

2. An electric lock for the levers of mechanical interlocking machineshaving preliminary locking comprising, a pivoted sector having a lockingshoulder, a U-shaped dog straddling said sector and arranged to engagesaid shoulder, and a curved strip fastened at its one end to said sectorand having inclined surf-aces adapted to engage said dog and force itinto position to engage said shoulder, said strip being clear of saiddog when said sector is in one extreme position, whereby said dog may bereadily inspected and removed.

3. In an interlocking system, the combination with a lever of aninterlocking machine, of an electric lock for said lever, said electriclock including an electro-magnetic operating means comprising cores ofmag netic material, an energizing winding on one end portion of eachcore, a single conducting yoke on the cores at the other end, andnonmagnetic insulating means for spacing said windings and yoke toprovide a leakage path for the flux produced by said windings andopposed by the magneto-motive-force due to current induced in said yokewhen said windings are energized by alternating current.

In testimony whereof I have afiixed my signature.

EDWVIN C. LARRY.

